are u my friend? The table below models the cost, y, of using a high-efficiency washing machine and a standard washing machine over x number of years. Which equation represents the cost of the high-efficiency washing machine over a given number of years? Which equation represents the cost of the standard washing machine over a given number of years? After how many years of use would the washing machines cost the same amount? Which washing machine would be the more practical purchase if kept for 9 years? ugh...

y= 25x+500

y=30x+400

20

standard machine

Step-by-step explanation:

just did it on edge!! :D

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

b. 153 students do not participate in sports and seventy-five 12th graders were surveyed